Consider a circle whose equation is x2 + y2 – 2x – 8 = 0. Which statements are true? Select three options.
1 answer:
The center of the circle lies on the x-axis
The radius of the circle is 3 units.
The radius of this circle is the same as the radius of the circle whose equation is x² + y² = 9.
<h3>How to determine the statements</h3>
The standard equation of a circle is expressed as:
Where
- Centre is (-g, -f)
- radius = √g²+f²-C
Given a circle whose equation is
Let's get the center of the circle
2gx = -2x
2g = -2
We have that;
g = -1
Similarly, 2fy = 0
given that
f = 0
Centre = (-(-1), 0) = (1, 0)
This explains that the center of the circle lies on the x-axis
We move further to the radius
r = radius = √g²+f²-C
radius = √1²+0²-(-8)
radius =√9
= 3 units
The radius of the circle is 3 units.
For the circle x² + y² = 9, the radius is expressed as:
r² = 9
r = 3 units
Hence the radius of this circle is the same as the radius of the circle whose equation is x² + y² = 9.
Learn more about circles here:
#SPJ1
You might be interested in